1. Field
The present invention relates generally to transmission control systems, and more specifically to a transmission control system that establishes a predetermined forward gear position.
2. Background
Various types of conventional transmission control systems are known in the art. For example, one such conventional transmission control system involves a twin clutch type transmission equipped with a synchro device, wherein rotation-restricting means are provided in first and second clutches located between a main input shaft and first and second auxiliary input shafts. According to this control system, when carrying out a pre-shift to a first speed gear position or a reverse gear position by operating the synchro device (such as when the vehicle is stationary), relative rotation between the synchro device and the gear is suppressed by the rotation restricting means. The rotation restriction means of this known solution thereby restricts rotation of the first and second auxiliary input shafts by causing drag torque of the first and second clutches, which are wet multi-plate clutches. This conventional solution provides a smooth pre-shift, and is described, for example, in Japanese Patent Application Laid-Open No. 2011-85244.
In the above-mentioned conventional arrangement, because it is necessary to provide special rotation restricting means in order to enable smooth operation of the synchro device, there is a large number of components, which produces a corresponding weight increase. Furthermore, in the above-mentioned conventional arrangement, even in a state in which rotation of the first and second auxiliary input shafts is restricted by the rotation restricting means, rotation of the synchro device is resisted due to the viscosity of lubricating oil attached to friction plates of the first and second clutches. Because of this, it is difficult to make phases of the gear and the sleeve of the synchro device interact smoothly.